The walls of combustion spaces which conduct hot gases such as those of the combustion chambers of gas turbine installations required a thermal shielding of the supporting wall structure against attack by the hot gases. The thermal shielding can for example be implemented by a lining resistant to hot gases placed in front of the actual wall structure in the form of a ceramic heat shield. Ceramic materials offer the ideal solution compared to metallic materials for constructing this type of heat shield because of the ability to withstand higher temperatures, resistance to corrosion and their lower thermal conductivity. The heat shield is generally constructed from a number of ceramic heat shield elements, which form a flat lining for the combustion space. A ceramic heat shield of this type is described in EP 0 558 540 B1 for example.
For operation of a combustion space and especially for operation of gas turbine combustion chambers the heat shield is exposed to extreme stresses. As well as thermal and mechanical stresses the heat shield elements are also exposed to heavily corrosive stresses as a result of the flow of hot gas. The corrosive loads can result in a loss of material on the heat shield element which reduces its lifetime. This loss of material is attributable to a combination of corrosion, subsequent post-sintering of the surface and erosive stress resulting from the high mass flow rate of flowing hot gas. In gas turbine combustion chambers the loss of material on the surface of ceramic heat shield elements is especially great in the transition area from the combustion chamber to the turbine.